Abstract: FR-PO807

Effect of Twice Weekly Hemodialysis on Plasma Levels of Uremic Solutes Normally Cleared by Secretion

Session Information

Category: Dialysis

  • 601 Standard Hemodialysis for ESRD

Authors

  • Leong, Sheldon, Stanford University/VAMC Nephrology, Palo Alto, Alabama, United States
  • Plummer, Natalie, Stanford University/VAMC Nephrology, Palo Alto, Alabama, United States
  • Meyer, Timothy W., Stanford University/VAMC Nephrology, Palo Alto, Alabama, United States
  • Sirich, Tammy L., Stanford University/VAMC Nephrology, Palo Alto, Alabama, United States
Background

Current guidelines allow twice weekly hemodialysis (HD) in patients with residual function. They require that patients receive a target standard Kt/Vurea (stdKt/V) calculated by combining the residual urea clearance (Kru) with dialytic dose assessed by Kt/Vurea. This urea-based calculation does not take into account the native kidney's secretory function. We hypothesized that because secretory function is not replicated by dialysis, plasma levels of normally secreted solutes may be better controlled in patients with residual function on twice (2X) weekly HD than in anuric patients on thrice (3X) weekly HD.

Methods

Dialytic clearance (Kd), residual clearance (Kr), and plasma levels for urea and 4 solutes normally cleared by secretion were measured in patients on 2X weekly HD with average stdKt/V 2.35 ± 0.49. Plasma solute levels were compared to those measured in anuric HEMO Study patients on 3X weekly HD with similar stdKt/V of 2.22 ± 0.24.

Results

Maintenance of secretion in the residual kidney was reflected by higher ratios of residual clearance to dialytic clearance (Kr/Kd) for the secreted solutes than for urea. The plasma levels for indoxyl sulfate, hippurate, and phenylacetylglutamine in the 2X weekly patients were significantly lower than in the 3X weekly anuric patients, while the plasma level for p-cresol sulfate was not different between the two groups (Table).

Conclusion

Residual kidney function removes a larger portion of secreted solutes than of urea. The plasma levels of secreted solutes may therefore be better controlled in patients with residual function on 2X weekly treatment than in anuric patients on 3X weekly treatment receiving the same weekly dose as assessed by Kt/Vurea. Consideration of secretory function may allow refinement of prescription guidelines for patients with residual kidney function.

 2X weekly
(n=9)
3X weekly
(n=469)
Kd
(ml/min)
Kr
(ml/min)
Kr/KdPlasma
(mg/dl)
Plasma
(mg/dl)
Urea Nitrogen235 ± 302.8 ± 1.50.01 ± 0.0167 ± 1860 ± 18
Secreted Solutes
 Indoxyl Sulfate28 ± 101.7 ± 1.40.08 ± 0.081.9 ± 0.92.7 ± 1.3 *
 p-Cresol Sulfate21 ± 80.7 ± 0.60.04 ± 0.044.2 ± 2.13.2 ± 1.8
 Hippurate122 ± 3314 ± 80.12 ± 0.092.7 ± 2.76.0 ± 4.7 *
 Phenylacetylglutamine160 ± 2910 ± 80.06 ± 0.062.3 ± 2.44.9 ± 3.2 *

(mean±stdev; *p<0.05, 2X vs. 3X weekly)

Funding

  • Veterans Affairs Support